您可以这样做，但不能使用类别。类别替换方法。 （警告，汽车比喻）如果你有一辆汽车，然后你摧毁那辆汽车并换上一辆新车，你还能使用旧车吗？不，因为它消失了，不再存在了。与类别相同。

You can do it, but not using a category. A category replaces a method. (Warning, car analogy) If you have a car, and you destroy that car and replace it with a new car, can you still use the old car? No, because it is gone and does not exist anymore. The same with categories.

您可以做的是使用Objective-C运行时在运行时以不同的名称添加方法（例如， bogusHitTest：withEvent：），然后交换 hitTest的实现：withEvent：和 bogusHitTest：withEvent：。这样当代码调用 hitTest：withEvent：时，它将执行最初为 bogusHitTest编写的代码：withEvent：。然后，您可以让代码调用 bogusHitTest：withEvent：，这将执行原始实现。

What you could do is use the Objective-C runtime to add the method under a different name at runtime (say, "bogusHitTest:withEvent:"), then swap the implementations of hitTest:withEvent: and bogusHitTest:withEvent:. That way when the code calls hitTest:withEvent:, it's going to execute the code that was originally written for bogusHitTest:withEvent:. You can then have that code invoke bogusHitTest:withEvent:, which will execute the original implementation.

所以伪造方法如下：

- (UIView *) bogusHitTest:(CGPoint)point withEvent:(UIEvent *)event {
  NSLog(@"executing: %@", NSStringFromSelector(_cmd));
  return [self bogusHitTest:point withEvent:event];
}

交换方法的代码将是：

Method bogusHitTest = class_getInstanceMethod([UIView class], @selector(bogusHitTest:withEvent:));
Method hitTest = class_getInstanceMethod([UIView class], @selector(hitTest:withEvent:));
method_exchangeImplementations(bogusHitTest, hitTest);